Issue checkstyle#14825: fix false positive for WhitespaceAroundCheck

strkkk · May 10, 2024 · e92ef06 · e92ef06
1 parent 14c818e
commit e92ef06
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Showing 6 changed files with 91 additions and 50 deletions.
diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/WhitespaceAroundCheck.java b/src/main/java/com/puppycrawl/tools/checkstyle/checks/whitespace/WhitespaceAroundCheck.java
@@ -71,6 +71,10 @@
  * of the catch block (left curly bracket) is not separated from the end
  * of the catch block (right curly bracket).
  * </p>
+ * <p>
+ * Note: <a href="https://openjdk.org/jeps/361">
+ * Switch expressions</a> are ignored by this check.
+ * </p>
  * <ul>
  * <li>
  * Property {@code allowEmptyCatches} - Allow empty catch bodies.
@@ -497,22 +501,37 @@ public void visitToken(DetailAST ast) {
      */
     private boolean isNotRelevantSituation(DetailAST ast, int currentType) {
         final int parentType = ast.getParent().getType();
-        final boolean starImport = currentType == TokenTypes.STAR
-                && parentType == TokenTypes.DOT;
-        final boolean insideCaseGroup = parentType == TokenTypes.CASE_GROUP;
-
-        final boolean starImportOrSlistInsideCaseGroup = starImport || insideCaseGroup;
-        final boolean colonOfCaseOrDefaultOrForEach =
-                isColonOfCaseOrDefault(parentType)
-                        || isColonOfForEach(parentType);
-        final boolean emptyBlockOrType =
-                isEmptyBlock(ast, parentType)
+        final boolean result;
+        switch (parentType) {
+            case TokenTypes.DOT: {
+                result = currentType == TokenTypes.STAR;
+                break;
+            }
+            case TokenTypes.LITERAL_DEFAULT:
+            case TokenTypes.LITERAL_CASE:
+            case TokenTypes.CASE_GROUP: {
+                result = true;
+                break;
+            }
+            case TokenTypes.FOR_EACH_CLAUSE: {
+                result = ignoreEnhancedForColon;
+                break;
+            }
+            case TokenTypes.EXPR: {
+                result = currentType == TokenTypes.LITERAL_SWITCH;
+                break;
+            }
+            case TokenTypes.ARRAY_INIT:
+            case TokenTypes.ANNOTATION_ARRAY_INIT: {
+                result = currentType == TokenTypes.RCURLY;
+                break;
+            }
+            default: {
+                result = isEmptyBlock(ast, parentType)
                     || allowEmptyTypes && isEmptyType(ast);
-
-        return starImportOrSlistInsideCaseGroup
-                || colonOfCaseOrDefaultOrForEach
-                || emptyBlockOrType
-                || isArrayInitialization(currentType, parentType);
+            }
+        }
+        return result;
     }
 
     /**
@@ -615,41 +634,6 @@ private static boolean isEmptyBlock(DetailAST ast, int parentType, int match) {
         return result;
     }
 
-    /**
-     * Whether colon belongs to cases or defaults.
-     *
-     * @param parentType parent
-     * @return true if current token in colon of case or default tokens
-     */
-    private static boolean isColonOfCaseOrDefault(int parentType) {
-        return parentType == TokenTypes.LITERAL_DEFAULT
-                    || parentType == TokenTypes.LITERAL_CASE;
-    }
-
-    /**
-     * Whether colon belongs to for-each.
-     *
-     * @param parentType parent
-     * @return true if current token in colon of for-each token
-     */
-    private boolean isColonOfForEach(int parentType) {
-        return parentType == TokenTypes.FOR_EACH_CLAUSE
-                && ignoreEnhancedForColon;
-    }
-
-    /**
-     * Is array initialization.
-     *
-     * @param currentType current token
-     * @param parentType parent token
-     * @return true is current token inside array initialization
-     */
-    private static boolean isArrayInitialization(int currentType, int parentType) {
-        return currentType == TokenTypes.RCURLY
-                && (parentType == TokenTypes.ARRAY_INIT
-                        || parentType == TokenTypes.ANNOTATION_ARRAY_INIT);
-    }
-
     /**
      * Test if the given {@code DetailAST} is part of an allowed empty
      * method block.

diff --git a/...esources/com/puppycrawl/tools/checkstyle/meta/checks/whitespace/WhitespaceAroundCheck.xml b/...esources/com/puppycrawl/tools/checkstyle/meta/checks/whitespace/WhitespaceAroundCheck.xml
@@ -48,6 +48,10 @@
  With this property turned off, this raises violation because the beginning
  of the catch block (left curly bracket) is not separated from the end
  of the catch block (right curly bracket).
+ &lt;/p&gt;
+ &lt;p&gt;
+ Note: &lt;a href="https://openjdk.org/jeps/361"&gt;
+ Switch expressions&lt;/a&gt; are ignored by this check.
  &lt;/p&gt;</description>
          <properties>
             <property default-value="false" name="allowEmptyCatches" type="boolean">

diff --git a/...est/java/com/puppycrawl/tools/checkstyle/checks/whitespace/WhitespaceAroundCheckTest.java b/...est/java/com/puppycrawl/tools/checkstyle/checks/whitespace/WhitespaceAroundCheckTest.java
@@ -260,6 +260,13 @@ public void testSwitchWhitespaceAround() throws Exception {
                 getPath("InputWhitespaceAroundSwitch.java"), expected);
     }
 
+    @Test
+    public void testSwitchExpressionWhitespaceAround() throws Exception {
+        final String[] expected = CommonUtil.EMPTY_STRING_ARRAY;
+        verifyWithInlineConfigParser(
+                getNonCompilablePath("InputWhitespaceAroundSwitchExpressions.java"), expected);
+    }
+
     @Test
     public void testDoWhileWhitespaceAround() throws Exception {
         final String[] expected = {

diff --git a/...checkstyle/checks/whitespace/whitespacearound/InputWhitespaceAroundSwitchExpressions.java b/...checkstyle/checks/whitespace/whitespacearound/InputWhitespaceAroundSwitchExpressions.java
@@ -0,0 +1,38 @@
+/*
+WhitespaceAround
+allowEmptyConstructors = (default)false
+allowEmptyMethods = (default)false
+allowEmptyTypes = (default)false
+allowEmptyLoops = (default)false
+allowEmptyLambdas = (default)false
+allowEmptyCatches = (default)false
+ignoreEnhancedForColon = (default)true
+tokens = (default)ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, \
+         BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND, \
+         LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, \
+         LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, \
+         LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, \
+         NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR, \
+         SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND
+
+
+*/
+
+package com.puppycrawl.tools.checkstyle.checks.whitespace.whitespacearound;
+
+import java.util.Optional;
+
+public class InputWhitespaceAroundSwitchExpressions {
+
+    Optional<String> someMethod(int arg) {
+        return Optional.ofNullable(switch (arg) { // ok - switch expression
+            default -> null;
+        });
+    }
+
+    Optional<String> someMethod2(int arg) {
+        return Optional.ofNullable(((switch (arg) { // ok - switch expression
+            default -> null;
+        })));
+    }
+}
diff --git a/src/xdocs/checks/whitespace/whitespacearound.xml b/src/xdocs/checks/whitespace/whitespacearound.xml
@@ -57,6 +57,10 @@ try {
           catch block (left curly bracket) is not separated from the end of the catch
           block (right curly bracket).
         </p>
+        <p>
+          Note: <a href="https://openjdk.org/jeps/361">
+          Switch expressions</a> are ignored by this check.
+        </p>
       </subsection>
 
       <subsection name="Properties" id="Properties">

diff --git a/src/xdocs/checks/whitespace/whitespacearound.xml.template b/src/xdocs/checks/whitespace/whitespacearound.xml.template
@@ -57,6 +57,10 @@ try {
           catch block (left curly bracket) is not separated from the end of the catch
           block (right curly bracket).
         </p>
+        <p>
+          Note: <a href="https://openjdk.org/jeps/361">
+          Switch expressions</a> are ignored by this check.
+        </p>
       </subsection>
 
       <subsection name="Properties" id="Properties">